Adapter Configuration for a Wind Tower Lattice Structure

ABSTRACT

A wind turbine tower includes a lattice tower structure having a plurality of vertically oriented columns and cross-brace members. An adapter is molded onto a top of the lattice tower structure such that top portions of the columns are embedded into the adapter. The adapter may be a concrete member molded onto the lattice tower structure.

FIELD OF THE INVENTION

The present invention relates generally to wind turbine towerstructures, and more particularly to an adapter configuration that mayutilized between the lattice tower and an upper tubular component of thewind turbine, or at the interface between a jacket foundation and towerfor offshore wind turbines.

BACKGROUND OF THE INVENTION

Conventional wind turbine towers typically include a tubularpoleconstruction to support a wind turbine at a considerable height tocapture wind energy. The tubular tower configuration is relativelysimple and easier to assemble, but utilizes a considerable amount ofmaterial, particularly steel. With the rising costs of these materials,the tubular towers become economically disadvantageous for certain hubheights and geographic regions.

The growing acceptance of wind energy as a significant alternativeenergy source depends on large part in maintaining the cost-per-kilowattof power produced at an acceptable level. In this regard, lattice towerstructures are gaining acceptance as a cost-effective alternative to theconventional tubular towers due, primarily, to significantly reducedamount of steel used in the lattice towers.

With certain conventional configurations, the wind tower structureincludes a lower lattice tower section and an upper tubular section,with the machine head mounted atop the tubular section. A steel adapteris provided at the interface between the lattice tower section and thetubular section. In another known configurations, the machine head issupported directly atop of the lattice tower section, also with anadapter provided between the lattice tower section and the machine head.An example of this configuration is the “Space Frame Tower™” from WindTower Systems of Park City, Utah, USA, wherein a steel interface flangeis welded to the top of the lattice tower. The yaw bearing ring in themachine head is bolted directly to this interface flange.

The interface between the lattice tower structure and the machine heador a tubular component that supports the machine head is crucial. Theload transfer issues from the machine head to the vertical legs of thelattice tower can be quite complex. It is the conventional practice touse a welded steel adapter at this interface, as with the configurationsdiscussed above. This steel adapter is, however, expensive to produceand requires skilled technicians (including welders) to configure theadapter to the tower, all of which adds to the overall cost of the windturbine.

The concerns are similar with respect to offshore wind tower structureswherein the towers are connected to lattice or girder structuresanchored to the sea bed with complex welded steel adapter structures.

Accordingly, an improved adapter configuration between the lattice towerstructure and the machine head structure that is cost-effective andpossesses superior load transfer capabilities is desirable.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In accordance with aspects of the invention, a wind turbine towerconstruction is provided having a lattice structure with a plurality ofvertically oriented columns and cross-brace members. An adapter ismolded onto a top of the lattice structure such that top portions of thecolumns are embedded into the adapter. The wind turbine tower structuremay be land-based on an off-shore installation.

The adapter is configured for connection with structure that supportsthe machine head (“nacelle”) of the wind turbine, such as a tubulartower component on which the machine head is mounted or a componentwithin the machine head. In this regard, the adapter may in oneembodiment include a plurality of anchor bolts embedded therein forreceipt of the tubular component. In another embodiment, a plurality ofbolt holes may be defined through the adapter for receipt of respectivebolts used to attach any manner of structure to the adapter. In still afurther alternative embodiment, a plurality of threaded inserts may beprovided in the adapter for receipt of a machine head component or othersupporting structure.

The adapter is not limited to a particular moldable material, and may beformed of any suitable settable, hardened material formed onto andaround the top portions of the columns. In a particular embodiment, theadapter is a concrete member poured and formed onto the top portions ofthe columns. In this concrete embodiment, any configuration of anchormembers may be attached to the top portions of the columns and embeddedin the concrete member. If anchor bolts are used in this embodiment,such bolts may be pre-tensioned in the concrete adapter.

The shape, dimensions, appearance, and the like, of the adapter are notlimiting factors of the invention. In a particular embodiment, theadapter is formed as a cylindrical plate-like member.

In a unique embodiment, the lattice structure includes a plurality ofvertically aligned and connected sections that may be erected at thewind turbine site. A top one of the sections may have the adapterpre-molded onto the columns.

It should be appreciated that the invention also encompasses a sectionof a wind turbine tower, wherein the section includes a plurality ofvertically oriented columns and cross-brace members interconnected todefine an open lattice structure, and with an adapter molded onto a topof the columns such that top portions of the columns are embedded intothe adapter. The adapter may be configured in various differentembodiments as discussed above.

The present invention also encompasses any manner of a wind turbine thatincorporates a lattice structure with an adapter as set forth herein.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a perspective view of a wind turbine with a lattice towerstructure that may incorporate an adapter configuration in accordancewith aspects of the invention;

FIG. 2 is a perspective view of an alternative embodiment of a windturbine with a lattice tower structure and adapter configuration;

FIG. 3 is a side cut-away view of a top portion of a lattice towerstructure with an adapter in accordance with aspects of the invention;

FIG. 4 is a perspective view of an embodiment of a lattice towerstructure with an adapter; and,

FIG. 5 is a perspective view of an alternative embodiment of a latticetower structure with an adapter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

FIGS. 1 and 2 are perspective views of exemplary wind turbines 10 thatmay be configured in accordance with aspects of the invention. Althoughthese wind turbines 10 are depicted as land-based structures, it shouldbe appreciated that the invention is not limited in this regard andincludes off-shore installations that utilize the adapter configurationand assembly in accordance with the invention. The wind turbines 10include a plurality of blades 12 mounted to a rotor hub 14, which inturn is rotationally supported by any manner of power generationcomponents housed within a machine head 16 (which is also referred to asa “nacelle”), as is well known in the art. The machine head 16 issupported atop a tower structure 18, which in the illustratedembodiments is an open lattice structure formed by columns or legs 20,horizontal braces 22, and diagonal braces 24. The columns 20 aretypically angle iron members or pipe members, and the braces 22, 24 aretypically angle iron members. These lattice frame tower structures 48are also referred to in the art as “space frame” towers. The latticetower structure 48 may be fabricated in sections and erected at the windturbine site.

In the embodiment of FIG. 1, the lattice tower structure 18 extendsessentially to the nacelle 16 such that the machine head components aresupported directly atop of the tower structure 18. An adapter 30 inaccordance with aspects of the invention is provided at the interfacebetween the lattice tower structure 18 and nacelle 16, as described ingreater detail below. It may be desired to provide a cladding material26 applied over the lattice tower structure 18, which may be any type ofsuitable fabric, such as an architectural fabric designed for harshweather conditions. The cladding 26 protects workers and equipmentwithin the tower and provides an aesthetic appearance to the windturbine 10.

In the embodiment of FIG. 2, the nacelle 16 is supported atop a tubularcomponent 38 that is, in turn, affixed to the lattice tower structure 18via an adapter 30. This adapter 30 may be in accordance with aspects ofthe present invention.

Referring to FIGS. 3 through 5 in general, the adapter 30 that isaffixed to the top of the lattice tower structure 18 is a moldedcomponent that is formed directly onto the top portions 32 of thelattice tower columns 20 such that the top portions 32 are embeddeddirectly into the adapter 30, as particularly illustrated in FIG. 3. Theadapter 30 may be molded from any suitable type of settable, hardenedmaterial that may be formed directly onto the top portions 32 of thecolumns 20, for example by being poured into a mold that is affixed tothe top of the lattice tower structure 18 during the fabricationprocess.

In a particular embodiment, the adapter is a concrete member, with thetop portions 32 of the columns 20 embedded directly into the concreteduring the formation process. It should be appreciated that concrete isnot a limiting material, and that other suitable types of settable,hardened materials may be used, for example, epoxies or other hardenedadhesives, hardened plastics, and so forth.

In order to strengthen and ensure the integrity of the connectionbetween the top portions 32 of the columns 20 and the adapter 30, it maybe desired to affix any manner of anchor members 34 onto the portions ofthe columns 20 that will be embedded in the adaptor 30, as depicted inFIG. 3. End plates or head plates may also be provided atop the columns20 for the same purpose.

It should be appreciated that the adapter 30 is not limited to anyparticular shape, size, dimensions, or aesthetic appearance, and thatall of these characteristics may be varied to the moldable and shapeablecharacteristics of the adapter 30. In the illustrated embodiment, theadapter 30 is a solid plate-like member, such as a concrete disc. Inother embodiments, the adapter 30 may be a ring so that cables, ladders,and any other component may be routed through the adapter into thetubular section or machine head.

In the embodiment of FIG. 2 wherein the adapter 30 is provided at theinterface of the lattice tower structure 18 and a tubular component 38,it may be desired to incorporate a plurality of anchor bolts 36 (FIG. 3)with the adapter 30. These anchor bolts 36 are configured for receipt ofthe bottom portion of the tubular component 38, as depicted in FIG. 3.The bolts 36 may be embedded directly into the adapter 30 and include athreaded extension that extends from the upper surface of the adapter30, as depicted in FIG. 4. In other embodiments, the anchor bolts 36 mayextend through holes that are drilled or formed into the adapter 30, asdepicted by the right-hand anchor bolt 36 in FIG. 3. The anchor bolts 36may be pre-tensioned within the adapter 30. It should be appreciatedthat the adapter 30 is not limited to any particular type of mechanicalfastening between the adapter 30 and the tubular component 38.

In the embodiment of FIG. 1 wherein the adapter 30 constitutes theinterface between the top of the lattice tower structure 18 and thenacelle 16, the adapter 30 may be configured for direct attachment withone of the machine components within the nacelle 16, such as the yawbearing ring. In this regard, referring to FIG. 5, the adapter 30 mayinclude a plurality of threaded inserts 44 for receipt of bolts used toattach the bearing ring to the adapter 30. In an alternative embodiment,bolt holes may be defined completely through the adapter 30, whereinbolts used to attach the bearing ring extend completely through theadapter 30 and are bolted at the underside of the adapter 30 similar tothe configuration depicted in FIG. 3.

The adapter 30 may, in certain embodiments, constitute a component thatis pre-formed onto a top section 40 (FIG. 3) of a lattice towerstructure 18, wherein various sections of the tower structure areassembled at the wind turbine site. In this manner, the adapter 30 maybe pre-formed onto a tower section 40 and transported intact with thetower section 40 to the wind turbine site. Alternatively, the adapter 30may be formed atop the lattice tower structure 18 at the wind turbinesite.

It should thus be appreciated that the present invention alsoencompasses any manner of a section 40 of a lattice tower structure thatincorporates an adapter 30 in accordance with aspects of the presentinvention.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A wind turbine tower construction, comprising: a lattice structurehaving a plurality of vertically oriented columns and cross-bracemembers; and an adapter molded onto a top of said lattice structure suchthat top portions of said columns are embedded into said adapter.
 2. Thewind turbine tower construction as in claim 1, wherein said adaptercomprises a settable, hardened material formed onto said top portions ofsaid columns.
 3. The wind turbine tower construction as in claim 2,wherein said adapter comprises a concrete member poured and formed ontosaid top portions of said columns.
 4. The wind turbine towerconstruction as in claim 3, further comprising anchor members attachedto said top portions of said columns and embedded in said concretemember.
 5. The wind turbine tower construction as in claim 1, furthercomprising a plurality of anchor bolts configured with said adapter. 6.The wind turbine tower construction as in claim 5, wherein said anchorbolts are pre-tensioned in said adapter.
 7. The wind turbine towerconstruction as in claim 1, further comprising a plurality of threadedinserts in said adapter.
 8. The wind turbine tower construction as inclaim 1, wherein said adapter is a continuous plate-like member.
 9. Thewind turbine tower construction as in claim 1, wherein said latticetower structure comprises a plurality of vertically aligned andconnected sections, said adapter pre-molded onto a top one of saidsections.
 10. A section of a wind turbine towerconsturction, comprising:a plurality of vertically oriented columns and cross-brace membersinterconnected to define an open lattice structure; and an adaptermolded onto a top of said columns such that top portions of said columnsare embedded into said adapter; wherein said adapter is configured forreceipt of a machine head component of a wind turbine.
 11. The sectionas in claim 10, wherein said adapter comprises a settable, hardenedmaterial formed onto said top portions of said columns.
 12. The sectionas in claim 11, wherein said adapter comprises a concrete member pouredand formed onto said top portions of said columns.
 13. The section as inclaim 12, further comprising anchor members attached to said topportions of said columns and embedded in said concrete member.
 14. Thesection as in claim 10, further comprising a plurality of pre-tensionedanchor bolts embedded into said adapter and configured for receipt of atubular component.
 15. The section as in claim 10, wherein said adapteris a continuous plate-like member.
 16. The section as in claim 10,wherein said adapter is a ring member.